All figures natural size.

Plate 40 MESOPLODON EUROPÆUS AND M. STEJNEGERI

Fig. 1. Stomach of Mesoplodon europæus. Atlantic City, New Jersey. Cat. No. 23346, U.S.N.M. Ventral aspect. About ¼ nat. size.

2. The same. Dorsal aspect. About ¼ nat. size.

3. The same. Perineum. a, penis. b, rudimentary mammary slits. c, anus. About ¼ nat. size.

4. Mesoplodon stejnegeri. Yaquina Bay, Oregon. Cat. No. 143132, U.S.N.M. Head, showing teeth in natural position.

Plate 41 MESOPLODON AND ZIPHIUS

Fig. 1. Mesoplodon europæus. Atlantic City, New Jersey. Male, young. Cat. No. 23346, U.S.N.M. Length 12½ feet.